Presses for producing continuous webs of material



M. WEISS March 18, 1958 PRESSES FOR PRODUCING CONTINUOUS WEBS OF'MATERIAL Filed Jan. 22. 1954 United States Patent O PRESSES FORPRODUCING CONTINUOUS WEBS OF MATERIAL Matthias Weiss, Vienna, Austria,assigner to Maschinenfabrik Andritz Actiengesellschaft, Graz-Andritz,Austria Application January 22, 1954, Serial No. 405,625

8 Claims. (Cl. 100-154) The present invention relates to a press forproducing continuous webs of material between two endless conveyor bandsor belts passing round a number of upper and lower rollers. A press ofthis kind is used mainly for removing the water from or for thickeningand cornpressing masses of wet fibrous material. By fibrous material isto be understood, for example, paper pulp, mechanical wood pulp,cellulose, wood shavings and other materials of a vegetable, animal ormineral nature. Some of these substances oppose considerable resistanceto the removal of the water, formation of a skin and compression, thisbeing so for instance when the substance is swollen or is more orY lessloose or contains stringy admixtures or constituents, such as, forinstance, peat, coconut husks or the like, or crumbly, crystalline orgranular constituents, such as vfor example in the case of certainground waste or by-products. The press can also be used however forpressing materials which are free from water consisting for example offilling substances and a synthetic resin binding medium.

One type of press has already been proposed in which the upper and lowerrollers are arranged in groups each consisting of two or more pairs ofoppositely lying rollers, the endsof the rollers of each group beingmounted in bearing plates adjustable as regards height. In order tobring about a thorough removal of the water and cornpression of thelmaterial in question very large pressing pressures have to be used andthis makes it necessary for the frame for the numerous rollers andparticularly the common beam yon which the bearing plates bear to be ofvery heavy construction.

According to the invention, in a press of theabovementioned kind, theopposite lying bearing plates are connected with one another by means oftension members, particularly screw-threaded spindles taking up thepressing pressure and the conveyor bands or belts form between them fromthe inlet of the press to the first pair of rollers a wedge-shaped inletspace. The tension members in question relieve the roller frame from thepressing pressure so that it has only to take the weight of the machinepartsso that it can be of considerably lighter construction. Moreover,resilient deformations under the inuence of the high pressing pressuresare effectively suppressed, this being absolutely necessary if highpressing pressures are to be obtained.

'In the construction of the present invention the supports for therollers and the'cross elements, which are usually provided for in thepresses of known type, are replaced by a number of bearing plates, thesetaking only the journals at the ends of the rollers and being of arelatively light construction.

A partial removal of the water or compression already occurs in thewedge-shaped inlet space formed according to the invention by theconveyor bands or belts so that the material for pressing enters theactual pressing part with a reduced volume and the pressing pressurebetween the rollers in the travel direction of the material can berapidly and effectively increased. An inlet space Patented Mar. 1s, 195sthe two bands is reduced and is correspondingly enlarged when thisdistance is increased.

One embodiment of the invention is illustrated in the accompanyingdrawing.

Fig. l is a vertical longitudinal sectional view of a pressV embodyingthe invention. Y

Fig. 2 is a cross-section kon the line II-II of Fig. 1.

Fig. 3 represents a half of a diagrammatical crosssection on the lineIIl-III of Fig. 1.

Fig. 4 shows a similar section through a slightly modilied form ofconstruction.

The material to be pressed is advanced between two endless conveyorbands or belts 1, 2 in the direction of the arrow in Fig. 1. Theseconveyor bands or belts consist of iexible sheet metal plates or thelike. The upper band 1 runs over the guide rollers 3, 4, 5 and atensioning roller 6 while the lower band 2 runs over the guide rollers7, 8, 9 and a tensioning roller 10. Fig. l shows roller groups A, B, C,D and E, each group being provided with four pairs of rollers 11, and anend group F.

The drawing is shown as broken between the groups D and E and any numberof further groups of rollers may be provided between these groups.

A horizontal beam 13 is xed at both sides of the press cn a frame 12,adjusting spindles 14 being mounted rotatably but not displaceably inthis beam at suitable distances apart. These spindles are provided atthe top and bottom with right and left-hand threads engaging with whichare nut members 15 rotatably mounted by means of journals 22 in thebearing plates' 16. Each two pressing rollers 11 bear on an intermediateroller 17 and with the exception of group A in the region of which thepressure is comparatively moderate, each two intermediate rollers 17bear against a middle roller 1,8 which transmits the pressing pressureto the corresponding bearing plate 16. Each of the bearing plates 16 isadjusted by actuating hand wheels 19 mounted on the spindles 14 enablingthe associated group of rollers to be displaced parallel to itself or tobe inclined diiTerently in the direction of travel of the material to bepressed. As shown in Fig. 2, each two spindles 14 lying opposite oneanother are coupled so that they have a common motion by means ofsprockets 2t) and a chain Z1, this ensuring that the positionV of therollers is always horizontal. Y

While the rollers 11 within a group lie in the groups A-D in a plane itwill be seen in group E these rollers are arranged along a curvedenvelope, facilitating the entry of the material to be pressed.

A Wedge-shaped inlet space 23 is'provided in front of the actualpressing part consisting of the groups A-F, this space being boundedlaterally by stationary, vertical side walls 24 and at the top andbottom by the bands or belts i, 2 extending between the rollers 4 and 5and 8 and 9. On the inside of the side walls 24 extend parallel to thebands l, 2 angled strips 25 in which are inserted resilient packingstrips 26, made forexample of porous rubber, these strips bearing with asealing action against the bands l, 2.

ln order to reduce the friction between the conveyor bands l, 2 andthese strips 26, thin sheet metal strips can be inserted between.Instead of strips 26 made of porous rubber or the like, as shown in Fig.3, sheet steel plates 28 stacked on top of one another can be used asshown in Fig. 4, the elasticity of which is retained and which are heldin place by their being cambered slightly in a transverse direction.

It may be of advantage if the sealing strips 26 or 28 are extended asshown in Fig. l into the actual pressing 3" part, for example, to thepoint 29 so that they also produce here a lateral edge sealing betweenthe bands 1 and 2.

sealing is generally no longer necessary for the portion ofthepressadjoining point 2911s the material is already well compressed at thispoint.

It can beseen that the material to be pressed is alreadly.` compressedor has the water removed from it in the inlet space 23, at least inpart. Linings are formed at this point on both the conveyor bands 1,2,these being squeezed together to form a homogeneous layer on` enteringthe pressing part. As shown in Fig. 1 two partitions 30, 31 provided inthe inlet space 23 these enabling a material of other composition to beintroduced between them, enabling webs of material to be obtained havingtwo cover layers and a diiierent kind of center layer. f only onepartition is used, this enables two-layer webs to be produced.

High degrees of compression can be obtained in a single operation withthe press according to the invention.

WhatI claim is:

1. A press for building up continuous webs of highly pressed material oflow moisture content from small loose particles, which comprises, incombination, a frame, a pair of endless flexible metallic perforatedconveyor bands forming vertically spaced-apart opposed runs, a pluralityof guide rollers` mounted in said frame and carrying said bands, theopposed vertically spaced-apart runs of o said bands being adapted tomove in the same direction, said opposed runs of said bands defining apressing cham ber in which the material being treated is continuouslyengaged by said bands and pressed while progressing with said bands, aplurality of pressing rollers engaged by and` driven by the saidconveyor bands exteriorly of said pressing chamber, `said pressingrollers having a smaller diameter `than said guide rollers and beingdisposed to bear against the portions of said bands between said guiderollers, said guide rollers directly actingt upon said opposed runs ofthe conveyor bands and urging both of said runs in the direction of themedial plane of said pressing chamber, supporting rollers supporting andbearing against said` pressing rolls in the direction of the medialplane of said pressing chamber, said pressing rollers and saidsupporting rollers being arranged` in` auplurality` of independentgroups arranged in spaced-apart series along said runs, each groupconsisting of1two units arranged at vertically opposite sides of saidpressing chamber and said runs, each unit comprising at least twopressing rollers and one associated supporting roller, and two laterallyspaced-apart bearing plates carrying the ends of said pressing rollersand the ends of said supporting rollers of each unit and therebycombining said pressingrollers and the corresponding supporting rollersin each unit, tensioning means acting solely on said bearing plates ofeach group for tensioning the opposite units of a group towards eachother, said tensioning means including means for effecting equaldisplacement of each of said opposite units of each group towards saidpressing chamber, each of said groups being adjustable `entirelyindependently of each other by said tensioning means.

In this case, it is an advantage if these strips, gradually decrease inthe direction of travel of the mate,-` rialtobepressed both in heightand width. An edge 2. A press as defined irtclam l, wherein saidtensioning means are formed from screw spindles, each spindle havingright-hand and left-hand threads, said screw spindles being guided insaid frame to prevent axial movement, the plates of one `unit of eachgroup having nut means engaging the right hand threads, and the platesof the other unit of each group having separate nut means engaging theleft hand threads so that by turning said screw spindles, equal movementof the opposite units of a group towards said pressing chamber iselected.

3. A press as defined in claim 1, wherein at least one of said endlessconveyor bands has a portion ahead of said guide rollers disposed infront of the said groups inclined to form one wall portion of awedge-shaped entrance chamber, stationary lateral Walls definingadditional wall portions of said wedge-shaped entrance chamber, andresilient sealing strips extending along said conveyor bands and securedto the said stationary walls, said strips bearing with a sealing, actionagainst the edges of said conveyor bands.

4. A press as defined in claim 3, wherein said sealing strips consist ofsheet lamellae stacked on top of one another.

5. A press as defined in claim 3, wherein said sealing strips consist ofsheet lamellae stacked on top of one another, said lamellae beingcambered in a transverse direction.

6. A press as defined in claim 3, wherein said sealing strips consist ofrubber, and strips of metal sheet are inserted between said first-namedstrips and said edges of the conveyor bands to reduce` friction,

7. A press as defined in claim 1, wherein at least one of said endlessconveyor bands has a portion ahead of said guide rollers disposed infront of said groups inclined to form one wall portion of a wedge-shapedentrance chamber, stationary lateral walls defining additional wallportions of said wedge-shaped entrance chamber,

, and resilient sealing strips `extending along said conveyor bands andsecured to said stationary walls, said strips extending along said runsand confining said pressure chamber, the height of said stripsdecreasing in the moving direction of said runs,` and said stripsbearing with a sealing action against the edges of said conveyor bands.

8. A press as defined in claim 7, further comprising at least onestationary partition inserted in said wedgeshaped entrance chamber andangularly subdividing said wedge-shaped entrance chamber to permit theproduction of webs of material consisting of several layers.

References Cited in the tile of this patent UNITED STATES PATENTS631,567 Fowler Aug. 22, 1899 1,638,981 Columbo` Aug. 16, 1927 1,778,342Thompson Oct. 14, 1930 1,782,214 Sheperd Nov. 18, 1930 1,806,006 Upsonet al May 19, 1931 2,142,932 Beard Jan. 3, 1939 2,554,988 Hollis May 29,1951 FOREIGN PATENTS 196,985 Switzerland July 1, 1938 253,752` GermanyNov. 14, 1912 498,197 France Oct. 9, 1919

